The Cozy MKIV is a self-built experimental aircraft with a lineage going back to the work of the legendary Bert Rutan in the late 1970s and early 80s. Rutan designed a long range, home made aircraft known as the Long-EZ. The pilot was in the front, the single passenger directly behind. Later, Nat Puffer decided to modify the plans to a more conventional 2 seat design he named the Cozy. Later still, Puffer extended the design to the Cozy MKIV – a four seater.
Nat Puffer sold out the rights to the Cozy range to Aircraft Spruce in the early 2000s, and it continues to be a popular plane for the self-build community, with many modifications to enhance the design. Many of THOSE can be found in links on my site.